Snap switch



0G12.- 20, 1936. Q 1 HATHORN 2,057,829

SNAP SWITCH Filed Sept. 19, 1935 2 Sheets-Sheet 1 2 ATTORNEY,

aOct. 20, 1936. A C, 1 HATHORN 2,057,829

SNAP SWITCH Filed Sept. 19, 1935 2 Sheets-Sheet 2 -65 90 91 HE 383/530@ Fgz 42 L [Z 321i 33 Fzq. I] H 667g ,I 96 71 Vl/ I /00 mi 9e I/Z/ 11 f lII H1 Il 72 n n elf! ITI ,I0 C] INVENTOR. Vere/1C@ J, Ha /wrn.

Patented Oct. 20, 1936 Heretofore,snap switches for controlling the 'power circuit of radio receiving sets have been constructed which have been of considerable size. With the advancement of the radio art, it has become necessary to construct a midget size snap switch which not only possesses the characteristics of large size snap switches, but also the switch must work eiiiciently for a long period of time. The problems involved in constructing a midget size type of snap switch wherein the external diameter of. the housing is approximately 111;" and whose thickness is approximately 1A, without the sacrifice of life'and accuracy of the switch are many. One, for example, is the allocation of the parts so that a minimum amount of space is occupied. Another problem is to construct the small switch of. parts which will withstandrough usage and still operate for a. long period of time.

It is, therefore, an object of my invention to construct a midget size of. snap switch which is adapted to be mounted upon an adjustable resistance device so that a single control shaft actuates both the adjustable resistance device and the snap switch, and wherein the snap switch is ct of my invention is to construct a pivot upon which the snap switch trigger and the bridging element throw arm is pivoted so that the pintle is rmly supported and it does not move out of position.

Another object of my invention is to mount the bridging member upon a ceramic pintle.

Another object of my invention is to construct a friction clutch between a control shai't and a snap-switch whereby the control shaft may be continuously moved inqeither direction without injuring the snap switch and wherein the snap switch may be actuated at a predetermined portion of the movement of the control shaft.

Another object of. my invention is to employ a base for a four-contact snap switch, wherein two outside terminals are generally employed, so that by shifting the four contacts, the switch base may be utilized for a switch which may be actuated by a counterclockwise moving actuator instead of a clockwise moving actuator or vice versa.

A further object is to construct a torsional spring which will hold itself in position.

A still further object is Another obje to construct a ,tran- UNITED sTATEs PATENT oFEicE sNaP swrrcn Clarence J. Hathorn, St. Marys, Pa., assigner-to The Stackpole Carbon Company, St. Marys, Pa., a. corporation o! Pennsylvania Application September 19, 1935, Serial No. l41,191 15 claims. (01.' zoo- 11) My invention relates to an electrical circuit controller and relates more particularly to a switch which opens or closes an electrical circuit.

This application is a continuation-impart oi 5 my aplication Serial No. 32,717, filed July l23,

siently actuated snap switch so that the switch actuating member is so insulated from the bridging member that the break-down is increased from approximately 500 volts to approximately 150()` volts. 5

Other objects of. my invention are to provide an improved device of the character described of simple and economical construction, and which possesses a maximum amount of serviceability and of strength. `l0

With the above and related objects in view, my invention consists of the details of construction and the combination of parts that will hereinafter be fully described when the description is read in conjunction with the accompanying draw- 1b ings in which:-

Fig. 1 is a plan view of a snap switch embodying my invention. v l

Fig. 2 is a sectional view taken on the line 2-2 0f Fig. 1. 20

Fig. 3 is a side elevational view of the pintle about which both the trigger and the throw arm pivots.

Fig. 4- is an exploded view of the elements comprising the, snap switch. i

Fig. 5 is a plan view of a modified type of bridging member, particularly employed in a two pole switch.

Fig. 6 is a schematic view of the stationary terminal members or rivets and the movable 30 bridging member of the switch which is illustrated in Fig. 4.

Fig. 'I is a schematic view of modified outside terminal connections for the switch shown in Fig. 4. 35

Fig. 8 is a schematic view of another modiilcation of the outside terminal connections as well as of the bridging members; thus, forming a double-pole single-throw switch.

Fig. 9 is a schematic view of. another modifica- 40 tion of the outside terminals wherein two terminalshave been shifted from the position illustrated in dotted lines, so that .one circuit is always closed.

Fig. 10 is a fragmentary sectional view of a 45 midget type of dual volume controls combined together with a snap switch. The dual volume controls are arranged in tandem and a spring type .of friction clutch is interposed between the control shaft and the snap switch, all of. the units 60 being controlled from a single shaft.

Fig. 11 is a diagrammatic plan view showing the relationship of the snap switch operating pin and its complementary trigger arms in both open circuit and closed circuit positions.

Fig. 12 is a schematic view of the movable bridging member and the stationary contacts, illustrating the position of the contacts in dotted lines when the trigger moves in one direction to close the circuit and the position of the contacts in full lines when the trigger moves in the opposite direction to close the circuit.

Referring now in greater detail to the drawings, in Fig. 1 is shown a midget type of snap switch wherein the overall diameter of the switch is approximately 111g and the overall thickness of the base is 1,/4". The switch mechanism hereinafter further described is mounted within a chamber of an insulated base, generally designated as A, which is preferably comprised of a molded phenolic condensation product. A body portion I 0 of the base is substantially fiat and from its periphery extends a flange I2 which is circular on its outer surface and which, also, extends perpendicular to the outer flat surface. The flange has a plurality of recesses or notches I4, I5 and I6 on the inner curved portion of the flange whichopens into the central chamber of the base. The function of the notches I4, I5 and I6 will be hereinafter described in conjunction with the various elements which they complement.

A plurality of small openings I8, 20, 2|, 22, 23 and 24 are formed in the base. The surface defining the opening 24, centrally located in the base, serves as a bearing for a ceramic pin or pintle, generally designated as B. The ceramic or insulation pintle B comprises a solid cylindrical shaft 26 about which an electrical bridging member, generally designated as C, oscillates and which also supports an insulating washer, generally designated as D, and an enlarged flat head 28 of the pintle retains the washer D and the bridging member C in position.

The openings 28, 2|, 22 and 23 are spaced from one another on the circumference of an imaginary circle which has its center in the axis of the opening I8 and within the openings 2D, 2|, 22 and 23, the shank of each of the electrical conducting rivets 30, 3|, 32 and 33, respectively, pass therethrough. Each of the rivets 30, 3|, 32 and 33 are similarly constructed'so that the description of one will suffice as a description of all the rivets. Rivet 30 has an enlarged curved head 35 which abuts against the inner fiat surface of the base body I0 and the rivets shank passes through both the opening 20 and an opening 3B in an electrical outside terminal 38, the terminal 38 has an end 48 bent to extend outwardly from the outside surface of the body whereby a exible electrical lead wire may be soldered, or otherwise suitably attached thereto.

The end of the rivet 30 adjacent the outside terminal 38 is expanded to retain the rivet, the terminal 38 and the base firmly together and also to establish a good electrical contact between the rivet and the terminal.

In the illustration in Fig. 2 the terminal 38 is electrically and mechanically connected to two rivets 30 and 3|, and another terminal 38, similar in construction to the terminal 38, is electrically and mechanically connected to the other two rivets 32 and 33. Other modifications of the outside terminal connections hereinafter will be described.

Within the opening I8 is located a shank 42 of a pintle, generally designated as E, the latter also being located to extend within the curved notch or recess I4 in the flange I2. Upon the pintle E is pivotally mounted an insulated throw arm, generally designated as F, 'and a trigger, generally designated as G, the latter being the actuated element of the snap switch whereby the switch is operated to open or to closed circuit positions.

The pintle E, see Figs. 2, 3, 4 and 10, has an enlarged shoulder 43 abutting the bottom of the notch I4 whereby the pintle is prevented from moving in one direction; adjacent the shoulder is a reduced cylindrical surface or'bearing 44 about which the throw arm F oscillates, and defining at One end the longitudinal length of the bearing 44 is another shoulder 46, the latter being of a greater diameter than the diameter of the bearing 44; a second bearing 48, above the second shoulder 46, interfits with an opening 41 in the switch trigger G so that the trigger oscillates about the above mentioned second bearing 48. A washer 58 rests upon a reduced shoulder 52 of the pintle E, and when an end 54 of the pintle is expanded with the elements in operative position, the washer 5U is held in position. The pintle is securely held to the base A when the pintle E has a shank 42 intertting with the opening I8 of the base and the lower end 58 is expanded.

A torsional spring, generally designated as H, has its central portion coiled, and its legs 5I), E2 straight and diverging from the coiled central portion. The tip 8| is offset from the leg 8U to engage a portion of the underside of the throw arm F, and since a portion of the leg 88 engages the uppermost side of -the throw arm, it is virtually impossible for the leg to jump out of the throw arm. The tip 83 of the leg 62 is offset from the leg in order to engage a portion of the uppermost portion of the flat body 64 of the trigger G and as a portion of the leg 62 engages the lowermost face ofthe trigger body 84 the leg B2 cannot jump out of the throw arm.

Movement of the trigger G does not actuate the bridging member C until the medial axis of the closed end of the spring passes slightly beyond dead center as the trigger compresses the spring arms of the torsional spring together. The energy stored in the spring after the dead center position of the spring is passed rapidly turns the throw arm as well as the bridging member, the latter either closing the electrical circuit when the terminals are bridged, or breaking `the circuit when the bridging member contact arms are moved away from the terminals. The torsional spring H not only moves the throw arm F with great rapidity but, also, presses the throw arm downwardly against the top of the ceramic pintles enlarged head 28, at all times; thus, the pintles head 28 presses the insulating washer D which in turn presses the hub of the bridging member C against the base IU thereby pressing the movable contact arms agains the stationary contacts.

The trigger G has a flat body 64 from which two spaced arms 65, B6 project at right angles thereto. 'I'he outer side of each arm 55, 66 abuts against a portion oi the angular wall 68, which defines a part of the notch I4 in the base flange I2, when the trigger G moves from one extreme position to its other extreme position, thus the angular wall 58 limits the movement of the trigger.

A pin "I0, suitably mounted on a volume control head 'II and connected toa volume control shaft 'I2 by means of a friction clutch, engages one of the arms 65 or E6, depending on the arm' complementary 10 and its complementary forked arms is de scribed in my cci-.pending patent application, Serial No. 754,587, led Nov. 24, 1934.

The throw arm F of insulating material has substantially a at body 14 wherein a plurality cf openings extend along the longitudinal axis of the body. An opening 15, on the longitudinal axis and adjacent one end of the throw arm is substantially circular and of a diameter to readily fit over the largest diameter 46 of the pintle E, in order to expedite the assembling of the throw arm upon the pintle during the course of manufacturing the snap switches. The circular opening 15 merges with an elongated slot 16 which is of a width whereby it may oscillate or pivot about the bearing 44 on the pintle E. The wall dening the slot 16 is shaped so that it may smoothly ride about the bearing, and it is to be noticed that the shoulders 42 and 46 are sufficiently spaced apart so that there is no unnecessary wobbling of the throw arm and also to enable the throw arm to move freely. A central small opening 11 in the longitudinal axis of the throw arm receives the tip of the leg 60 of the torsional spring H. Another opening 18 receives a tongue or upturned portion 80 of a lever arm 8| of the bridging member C. The end 82 of the throw arm rides within the notch I6 of the base and engages either of the side walls 85 and 86, which also aid to define the notch I6, thus the side walls 85 and 86 limit the movement of the throw arm.

The bridging member C, of electrical conducting material, has a flat central hub 88 from which a plurality of at contact arms 90, 9| and 92 and 93 radially extend. The bridging member has a central opening 94 through which the ceramic pintle B passes; and the arms 90, 9|, 92 and 93 are located so that they may simultaneously wipe and, also, contact the rivets 30, 3|, 33 and 32, respectively, whereby the circuit is completed at four points. The side edges adjacent the o-uter portion of each arm are curved upwardly to enable the arms to freely wipe their stationary contacts or rivets.

An inspection of Figs. l and 2 will reveal that the porcelain pintle B .and the micarta washer D completely vinsulates the trigger G from the bridging member C. With the arrangement of elements as described, the breakdown Vvoltage is approximately I1500 volts; whereas, the omission of the insulation reduces'the breakdown voltage to approximately 500 volts. If an electrical conducting pintlewere used, then'the live portion of the circuit would be brought closer to the trigger.

In Fig. l I illustrate a tandem arranged set of volume controls, generally designated as VI and V2, of the adjustable resistance type, combined together with a snap switch. Each instrumentality is actuated from a single control shaft 12. For the purposes of this application, the details of construction of the volume controls will be omitted since thel subject matter therein is set forth in my co-pending application Serial No. 32,717, filed' July 23, 1935; It is sufficient to, state here that the volume' control head 1 I, which carries the pin 10, is not fixedly secured to the control shaft 12 but is actuated by the frictional force imposed thereon by vvirtue ofthe helical spring 96 which presses the volume head 1| against a washer 9,8 and the spring 96 also presses against the second volume control head |00, the latter, also, being freely rotatable about the control shaft'12. The pin 10 suitably fastened upon are to be received the upper volume control head 1| ltransiently engages one arm of the forked trigger G to actuate the trigger.

In Fig. 6 I illustrate diagrammatically the electrical connection of the switch when in a radio receiving circuit. This is a single throw, single pole switch used in contro-lling the power input on AC or AC-DC radio receiving sets.

The circuit illustrated in. Fig. 7 is mainly used in controlling battery sets. In battery radio sets it is common practice to connect the negative A battery terminal to the negative B battery terminal, and the positive A battery terminal to the proper filament connection, and the positive B battery terminal to the proper tube plate connection. In many cases, it is desirable to separate the two batteries entirely when the set is turned off. The connection shown in Fig. 7 is ideally suited for this circuit application. For instance,vthe negative A terminal might be tied to switch terminal 33 and the negative B terminal connected to switch terminal 32. Then when the switch is opened, it can be readily seen that the two battery circuits are separated entirely. However, when the switch is closed, the terminals 30 and 3|, being electrically tied together toI form a single connection, serve as a common negative connection for the two batteries.

Fig. 8 is a further elaboration of Fig. 7, in which all of the four outside terminals are separated when the switch is open. However, two contact arms |02, |03 are electrically connected and form a pole C2, and contact arms |04, are electrically connected together and form a pole CI. Each set of contacts |02, |03 and |04, |05 are mounted upon aninsulated hub DI, thus forming a two pole switch.

In Fig. 12 I show the rivet terminals shifted in a clockwise direction. If the terminals were located in the position illustrated by the circular dotted lines, the switch would be in closed circuit position if the trigger would be moved counterclockwise. Whereas in the new position shown in full lines, the circuit will be broken when the trigger is moved clockwise. "Thus, by shifting the openings for the rivets, the switch can be made so that its on and ofl'positions are reversed. This universal base is desirable since in some combined volume control and snap switch units the switch is off when the control shaft is moved counterclockwise, whereas by the changes hereinabove set forth, the switch will bein an off position when it has been moved to its extreme clockwise position.

In Fig. 9 I show another modification of my snap-switch invention, wherein the two pole bridging member of Fig. 5 is employed as well as three or four outside terminals. In the schematic view, one circuit is through stationary contacts 3|, 33 and another circuit is through terminals 30, 32. However, the stationary contacts 30, 32 are shifted from their dotted line position to that shown in full lines to enable the circuit through contacts 30, 32 to be opened when the circuit through contacts 3|, 33 is closed.` Of course, when the circuit through contacts 3|, 33 is open, the circuit through contacts 30, 32 is closed. This type of switch may be utilized in-illuminating one portion of a dial when broadcasting electric waves and the other portion of the switchlmay be used to illuminate another portion of the same dial when short electric waves are set forth may be used for numerous types of switches for controlling different types of circuits instead of constructing a plurality of different bases for the different types of switches.

In Fig. 4 I may optionally use four terminals instead of two terminals so that each of two circuits can be broken, at two different points.

For the purpose of emphasis by repetition, it is to be observed that the ceramic pintle B is held in position only bythe frictional engagement of the upper surface of its head 28 against the bottom surface of the throw arm F irrespective of whether the switch is'in open or in closed circuit positionthe lower portion of the head of the ceramic pintle in turn presses the insulating washer against the hub 88 of the bridging member C. Thus, the bridging member or switch spider C oscillates about the ceramic or porcelain pintle B as its center, and the arms of the bridging member wipe against the curved rivet heads, thus keeping a clean contact, when the circuit is completed or broken.

The control shaft 'l2 (Fig. 10) may be continuously moved in either clockwise or counterclockwise direction, but the pin 10 will abut either of the spaced arms 65, 66 to limit the pins movement; thus, since the longest angular distance between the arms 65 and 66 is less than 360, the pin 10 can only be moved less than 360 whereas the control shaft may be moved any multiple of 360. For example, referring to Fig. 11, suppose the pin 1U is rotated in a clockwise direction, then pin Ill engages the arm 6B and moves the trigger G to the position illustrated in broken lines; further clockwise movement results in the pin abutting the outside surface of arm 65, thus limiting the pins movement-however, the shaft l2 may be continuously rotated in a clockwise direction. A similar action occurs when the pin is revolved in a counterclockwise direction except that the arms 65, 66 are in a reversed position as compared to the operation hereinbefore set forth.

Although my invention has been described in considerable detail, such description is intended as illustrative rather than limiting, since the invention may be variously embodied, and the scope of the invention is to be determined as claimed.

I claim as my invention:-

l. `A snap switch comprising an actuating trigger, a throw arm, and a spring joined to said trigger and said throw arm whereby a snap action to the throw arm will be imparted by movement of the trigger beyond a predetermined point, a bridging member adapted for said snap switch, comprising a flat hub and a plurality of flat contact arms radially extending from said hub, a lever arm radially extending and joining the hub whereby the bridging member is moved, a base comprising a at body portion, an annular flange extending substantially at right angles to said body portion, a curve surface formed in said flange and adapted to house a trigger and, a plurality of recesses in said flange, one of which is to allow free movement of a spring, and the other of which supports a throw arm and also limits the movement of the throw arm.

2. A snap switch comprising an insulated base, a plurality of ystationary contact members mounted in said base, a bridging member adapted to engage and to be disengaged from said stationary contact members, a ceramic pintle mounted in said base about which said bridging member oscillates, an enlarged head on said pintle and pressing the bridging member against the insulating base, a throw arm and a trigger pivotally mounted, and a spring connected between said trigger and said throw arm whereby rapid movement will be imparted from said trigger to said throw arm, said throw arm resting on the head of said pintle, and means whereby movement of the throw arm will impart movement to the bridging member.

3. In a snap switch, a plurality of complementary stationary terminals and movable bridging terminals, means to move said bridging member comprising a trigger and a throw arm, a pintle about which said trigger and throw arm pivot, said pintle comprising two spaced shoulders dening a bearing therebetween for the throw arm, and one of said shoulders also serving as a rest for the trigger.

4. In a snap switch, a plurality of xed contacts, a movable bridging element to engage said contacts, a throw arm mounted upon a pintle, a trigger arm mounted upon the same pintle, an

insulating base having a plurality of notches therein, one of said notches having its end walls limiting the movement of the trigger, a second notch having an end of the throw arm oscillate therein, and the side walls of said last named notch serving to limit the movement of the throw arm.

5. In a snap switch, a base of insulating material having a peripheral flange thereon, a plurality of notches in said flange communicating with the central chamber defined by said fiange and the body portion of said base, a ceramic pintle loosely mounted in the center of said base, a bridging member pivotally mounted about said ceramic pintle, a plurality of stationary contacts mounted on said base and being adapted to be engaged by said bridging member arms, a pintle in one of said notches, a throw arm and a trigger mounted on said pintle, a spring interposed between said throw arm and trigger whereby rapid movement will be imparted to said throw arm, said throw arm riding upon the ceramic pintle head whereby the bridging member will be pressed downwardly against the insulating base wherein the stationary contacts are mounted, the other end of said throw arm movable in another of vsaid notches and being adapted to engage one or the other of the side walls aiding in defining the notch whereby the throw arm will be limited in movement, an intermediate portion of said spring also movable in another notch in said flange and, means between said throw arm and said bridging member whereby movement of the throw arm will impart rotary movement to the bridging member.

. 6. In a snap switch, a base of insulating material havinga periphery flange therein, a plurality of notches in said flange communicating with the central chamber defined by said flange and the body portion of said base, a ceramic pintle loosely mounted in the center of said base, a bridging member pivotally mounted about said ceramic pintle, a. plurality of stationary contacts adapted to be engaged by said bridging member arms, a pintle in one of said notches, a throw arm and a trigger mounted on said pintle, a spring interposed between said throw arm and trigger whereby rapid movement will be imparted to said throw arm, said throw arm riding upon the ceramic pintle head, whereby the bridging member will be pressed downwardly against the insulating base wherein the stationary contacts are mounted, the other end of said throw arm movable in another of said notches and being adapted to engage one or the other of the side walls aiding in defining the notch, whereby the throw arm will be limited transiently movable an opening in said -and said throw arm in movement, an intermediate portion of said spring also movable in another notch in said flange, a rotatable control shaft, a loosely fitting member mounted on said control shaft and having a' pin interfitting with the trigger whereby the switch is actuated mounted upon said control shaft, and a friction clutch interposed between said control shaft and said actuating pin.

7. In combination a control shaft, a friction clutch, and a snap switch, means for transiently actuating said snap switch either to open or to closed circuit position, said means including a forked pivoted member and a pin and being located between said friction clutch and said snap switch, said snap switch comprising an insulating base, a plurality of fixed contacts in said base, a. bridging member complementing said fixed contacts, a lever arm joined to said bridging member, a ceramic pintle loosely interfitting with mounted, a spring having its ends connected to said throw arm and said forked pivoted member whereby ra'pid movement will be imparted to said throw arm, said throw arm having an opening whereby the lever arm of the bridging member interiits, and said throw arm also pressing against the ceramic pintles head whereby the pintle presses the bridging member Iagainst the fixed contacts when the switch is inclosed circuit position.

8. A snap switch adapted to` be actuated by a pin comprising an insulated base, an electrical bridging member adapted to engage or to be disengaged from said stationary contact members, a throw arm and a trigger pivotally mounted, means between said throw arm and said bridging member whereby the throw arm will move said bridging member, a flat spring between said throw arm 'and said trigger whereby rapid movement will be imparted to said throw arm from said trigger, and an end of said flat spring having an offset thereon whereby the cifset engages the outer surface of the trigger and another portion'of the same end engages a portion of the lower surface of the trigger and an offset on the other end of said flat spring whereby the offset engages the lower surface of said throw arm and another portion of the second named end engages a portion of the upper surface of the throw arm.

9. A snap switch adapted to be actuated by a transiently movable pin, said switch comprising an insulatedbase, a plurality of stationary contact members mounted in said base, a bridging member having a flat hub and a plurality of radially extending contact arms and a lever arm, a porcelain pintle having an enlarged head about which said bridging member may rotate, a micarta washer disposedv between the hub of said bridging member and the pintle` head, a throw arm having an opening therein which receives the bridging members lever arm whereby the throw arm moves the bridging member, a metallic trigger adapted to be engaged by said movable pin, and a spring interposed between said trigger 10. A snap switch comprising an insulated base, a plurality of stationary contact members mounted in said base, a bridging member adaptedto engage and to be disengaged from said stationary contact members, a ceramic pintle base, a throw arm pivotally whereby rapid movement will be imparted to said throw arm from said trigger.

mounted in said base about which said bridging member oscillates, an enlarged head on said pintle and pressing the bridging member against the insulating base, a throw arm and a trigger pivotally mounted, and a spring connected between said trigger and said throw arm whereby rapid movement will be imparted from said trigger to said throw arm, said throw arm resting on the head of said pintle, said spring having two diverging legs, one leg having an offset thereon whereby the offset engages the outer surface of the trigger and another portion of the same leg engages a portion of the lower surface of the trigger, and an offset on the other end of the second leg whereby the offset engages the lower surface of said throw arm and another portion of the second named leg engages a portion of the upper surface of the throw arm.

1l.v In combination a rotatable shaft, a snap switch including a movable trigger having spaced members thereon, a friction clutch interposed between said shaft and snap switch, and a stud on said friction clutch to engage one or the'other of said trigger spaced members, said shaft being adapted to rotate said stud to transiently engage said trigger at a predetermined portion of its rotative cycle.

12. A snap switch comprising an insulating base, a forked snap switch trigger, pivotally mounted whereby said trigger may oscillate a throw arm, said throw arm being pivotally mounted, a spring connected to the trigger and throw arm to impart rapid movement to the throw arm, an electrical bridging member, a pintle located in said insulating base, said pintle having an enlarged head, said bridging member being pivotally mounted on said pintle and being engaged by the enlarged head,flxed terminals adjacent the inside surface of said base and being adapted to be engaged by said bridging member, a throw arm bearing against the head of the pintle and pressing the bridging member in a direction towards the base of the snap switch, and a lever arm connected to said bridging member and said throw arm and being movable by the movement of the throw arm, said spring also being adapted to press the throw arm against the head of the pintle whereby said pintle will press said bridging member towards the base and/or the fixed terminals in said base.-

13. In combination, av snap switch, a rotatably mounted control shaft, a friction clutch interposed between said control shaft and said snap switch, and means whereby said ,control shaft is adapted to open the snap switch at a predetermined portion of its cycle of rotation and to close the snap switch at the same portion of its cycle of rotation in the opposite direction, said shaft also being adapted to be continuously rotated in either direction.

' 14. A snap switch comprising an insulated base, a plurality of stationary electrical contact members mounted in said base, an electrical ,bridging member adapted to engage and to be disengaged from said stationary contact members, an insulating pintle loosely mounted in said base and about which said bridging member oscillates, an enlarged head on said pintle and pressing the bridging member against the insulating base or the stationary terminals, a throw arm and a trigger pivotally mounted, a spring connected between said trigger and said throw arm whereby rapid movement will be imparted from said trigger to said throw arm, r`said throw arm resting on the head of said pintle, and means whereby movement of the throw arm will impart movement to the bridging member.

15. In combination a control shaft, a friction clutch, and a snap switch, means for transiently actuating said snap switch either to open or to closed circuit position, said means including a forked pivoted member and a pin and being located between said friction clutch and said snap switch, said snap switch comprising an insulating base, a plurality of xed electrical contacts in said base, an electrical bridging member complementing said xed electrical contacts, a lever arm joined to said bridging member, an insulating pintle loosely interfitting with an opening in said base, an enlarged head on said pintle, a throw arm pivotally mounted, a spring having its ends connected to said throw arm and said forked plvoted member whereby rapid movement will be imparted to said throw arm, said throw arm having an opening with which a portion o! the lever arm of the bridging member interflts, said throw arm also pressing against the insulating pintles head whereby the pintle presses the bridging member Aagainst the xed contacts when the switch is in closed circuit position, and said friction clutch disposed between said control shaft and said means Ior transiently actuating said snap switch.

CLARENCE J. HATHORN. 

